The present invention relates to a deburring tool, of a manual or hand-held character, which may be utilized to remove burring or flashing from metal workpieces, such as may result from drilling, milling, punching, or initial forming of the workpiece article.
2. Description of the Related Art
In the field of fabrication of structural elements and articles, involving milling, drilling, machining, and related fabrication or forming operations, workpieces are produced having burring or flashing at the locus of processing, which is required to be removed to render the workpiece article satisfactory for subsequent usage.
If such burring or flashing detritus is not removed, the resulting article may not adequately mate with cooperative parts in a desired assembly comprising the workpiece article, or the fit of such article in its desired end use application structure may not be accommodated.
In addition to difficulties of use created by such extraneous residual material produced in the processing of the workpiece, the burr or flashing may also represent a hazard, as for example in the case of metal structures, in which the burr or flashing surrounding drilled holes may damage or injure persons or things coming into contact therewith. Similar hazards are also present when tapping or other machining operations are employed to finish the workpiece article.
The burring or flashing resulting from edge cutting or shaping of workpiece articles may involves a linear cut or edge profile which is readily amenable to sanding, grinding, or other deburring operations for removing the burr or flash material. In the case of drilled, punched, or tapped openings, particularly of circular cross-section, e.g., in the formation workpiece articles comprising plate stock, it is common practice to utilize hand-held deburring tools.
A wide variety of deburring tools has been devised and is in common use, particularly in metal machining operations, e.g., those involving drilling or tapping of aluminum plate stock or other sheet metal elements.
A "Scraper and Deburring Tool", MSB-1161, is commercially available from Industrial Pipe & Steel Company (South El Monte, Calif.). This tool includes a stylus-type handle serving as a holder for a longitudinally extending tip member, of general pencil-like shape, having a conical distal tip and a cylindrical main body with a series of circumferentially spaced-apart, longitudinally-extending ridges. This tool thus serves as a drilled hole reamer or grinding means for removing burring or flashing. A disadvantage of this type of tool is that it must be manually rotated to effect the desired deburring or deflashing action. Thus, its extent of rotation in a single turn is limited by the arc of the user's wrist movement, which is generally less than 270.degree. arc length in a single turn. Following an initial turn, the tool must be released and the user's hand must be repositioned to effectuate a new turn. This presents difficulties in terms of the ease and speed of use of such tool.
A deburring tool set is available from the same manufacturer (Industrial Pipe & Steel Company, South El Monte, Calif.), which comprises a generally cylindrical handle, a shaft-like telescoping holder, and deburring blades of generally flattened S-shape. The blade comprises a first segment coaxially alignable with the telescoping holder, which in turn is coaxially positionable in the handle. The opposite extremity of the blade is elongated in form, with a longitudinal axis parallel to the first, coaxial segment, but radially displaced therefrom, with an intermediate angular connecting segment between the respective end segments. The distal extremity of the blade features a deburring surface. In the use of this tool, the blade is reposed at its proximal end in the telescoping holder, which in turn is mounted in the handle. The handle then is rotated relative to the distal extremity of the deburring blade, in the manner of a brace-and-bit hand drill. Rotary motion thereby is imparted to the deburring surface at the distal extremity of the blade, whereby burring or flashing is removable from a hole in which the distal blade extremity is positioned. While this device overcomes the deficiencies of the stylus-type deburring tool described hereinabove, the off-set character of the handle of such tool and its impartation of rotation to the distal deburring surface through a laterally extended arm (i.e., the intermediate connecting segment of the blade element) results in the overall device being somewhat unwieldy. As a result, in the operation of this device, the deburring blade has a tendency to jump or laterally disengage from the hole in which it is disposed, causing scoring of the surrounding surface of the workpiece article, or at the least involving loss of time and efficiency, and requiring expenditure of some effort to overcome the inherent clumsiness of such tool. Further, the off-set character of the overall device creates an accessibility problem, in instances where the structure surrounding the workpiece portion bearing the flash-bearing hole is difficult to access other than in a direct or linear fashion (in such instances, the stylus-type deburring tool previously described could be suitably employed, but with the previously mentioned deficiencies attendant its use).
A similarly constructed deburring tool is available as Speed Deburring Tool No. SP275 from Aircraft Tool Supply Company (Monroe, La.). This tool also uses a radial off-set arrangement, and comprises a handle member to which a proximal coaxial shaft segment is joined. The distal end of this first segment is connected to a laterally outwardly and downwardly extending slant arm intermediate portion, which at its distal portion is connected to a linear distal portion which is parallel to (and laterally displaced from) the first segment and the handle in which the first segment is reposed. At the extremity of the distal segment is mounted a deburring element. The deburring element comprises a main cylindrical body portion, of greater diameter than the distal segment to which it is joined, and having a conical extremity with a deburring structure on its exterior surface. This deburring tool, of similar configuration to the Deburring Tool Set which is commercially available from Industrial Pipe & Steel Company, suffers from the same deficiencies as described above in its intended use. Further, the Speed Deburring Tool of Aircraft Tool Supply Company features the tip element as a threaded member attaching to the off-set proximal segment of the extension member joined to the handle. The tip element thus is specific to such Speed Deburring Tool, and cannot accommodate the wide variety of deburring tip elements which are widely commercially available.
Such deburring tip elements generally are of standard sizes including 1/4 inch, 5/8 inch, and 1/2 inch) with other sizes (3/16 inch, 5/16 inch, 5/8 inch, 3/4 inch, and 7/8 inch, also being available. These deburring tip elements generally feature a longitudinally extending shank portion of suitable material, as for example hardened steel, which at its distal end is joined to the tip member. This tip member generally comprises a short cylindrical portion forwardly of which is provided a conical-shaped cutting portion featuring ridges, grooves, and blade surfaces, as appropriate to the deburring operation.
These deburring tip elements are adapted for use in power drills, such as hand-held electric drills, wherein the tip element is utilized in the same fashion as a drill bit, with respect to its retention by the drill.
The difficulty of using such deburring drill bits in an automatic or power drill relates to the fact that power drill speeds are generally relatively high, even in the case of variable-speed drills. It frequently is difficult to avoid deburring or deflashing a hole or opening, without doing damage to the workpiece by undesired penetration of the deburring tip element into the workpiece surrounding the hole being deburred. Further, for the same reason of relatively high rotational speed, such deburring tip elements in practice frequently "jump" from the hole and score or otherwise mar the surrounding workpiece surface, or otherwise are difficult to manually control with a hand-held power drill.
The foregoing problems may be alleviated to some extent by use of a drill press in which the deburring tip element is employed, wherein the depth of penetration of the deburring tip element is selectively fixed by mechanical adjustment of the drill press arm in a conventional manner, but this requires the substantial capital investment and operational expense of a drill press apparatus, and such apparatus moreover cannot readily accommodate large-sized workpiece articles.
Deburring tip elements with a wide variety of shapes other than the conical-tipped deburring tips described above, are also available, including olive-shaped tips, tree-pointed shaped tips, cylindrical radius end-shaped tips, U-shaped concave radius deburring tips, inverted conical tips, etc., as widely available from a variety of commercial sources, as for example Miller Industrial Tools, Inc. (Van Nuys, Calif.).
It would therefore be a significant advance in the art to provide a deburring tool which is hand-held in character, simple in construction, and free of the off-set articulated extension arms utilized in prior art hand-held deburring tools, and which is readily adaptable to accommodate a wide variety of commercially available deburring tip elements featuring a cylindrical shank of appropriate size (diameter).
It therefore is an object of the present invention to provide a hand-held deburring tool of such type.
Other objects and advantages of the present invention will be more fully apparent from the ensuing disclosure and appended claims.